Peroxygen bleach-containing compositions have been extensively described in laundry applications as laundry detergents, laundry additives or even laundry pretreaters.
Indeed, it is known to use liquid compositions comprising a peroxygen bleach and a bleach activator in laundry pretreatment applications. Although said liquid bleaching compositions provide good bleaching performance when used to pretreat a soiled fabric, there is still some room to further improve them regarding for example the stains/soils removal performance delivered when pretreating said soiled fabric.
It is thus an object of the present invention to provide improved stain removal performance on a variety of stains/soils under pretreatment conditions, i.e., when applied directly onto the soiled fabrics, and left to act onto said fabrics before washing said fabrics. More particularly, it is an object of the present invention to provide liquid compositions containing a peroxygen bleach and a liquid hydrophobic bleach activator, which deliver improved stain removal performance on a variety of stains/soils under pretreatment conditions while not compromising on their bleaching performance.
It has now been found that the above object can be met by using a liquid composition (pH=0 to 7) comprising a long chain (C12-C16) acyl sarcosinate to pretreat soiled fabrics. Indeed, it has been found that the addition of a long chain (C12-C16) acyl sarcosinate in a liquid composition (pH=0 to 7), e.g., in a liquid composition comprising a peroxygen bleach and optionally a liquid hydrophobic bleach activator, allows to deliver improved stain removal performance on fabrics under pre treatment conditions, as compared to the stain removal performance delivered by the same composition without said long chain acyl sarcosinate or to the same composition but with another anionic surfactant like for instance C12 alkyl sulfate instead of said long chain acyl sarcosinate. Thus in its broadest aspect, the present invention encompasses the use of said long chain acyl sarcosinate, in a liquid composition (pH=0 to 7), for improving the stain removal performance of said composition under pretreatment conditions. The present invention also encompasses liquid compositions comprising said long chain acyl sarcosinate, a peroxygen-bleach and a liquid hydrophobic bleach activator. Indeed, it has further been found that the addition of said long chain acyl sarcosinates, in the liquid peroxygen bleach-containing compositions of the present invention comprising said liquid hydrophobic bleach activator, contributes to emulsify said hydrophobic bleach activator so that said compositions are formulated either as microemulsions or as emulsions. Thus, the compositions according to the present invention allow to provide improved stain removal performance when pretreating soiled fabrics while exhibiting also excellent chemical stability, even upon prolonged storage periods.
An advantage of the present invention is that the improved stain removal performance obtain ed when pretreating fabrics with the compositions of the present invention is noticeable on a variety of stains/soils including greasy/oil stains, like make-up, lipstick, dirty motor oil and mineral oil, greasy food like mayonnaise and spaghetti sauce, bleachable stains like tea, wine, grass and enzymatic stains like blood.
EP-A-677575 discloses liquid compositions formulated as emulsions comprising two phases, each phase comprising a nonionic surfactant, said compositions comprising a peroxygen bleach in one of the phases and a bleach activator in the other phase, said compositions further comprising an anionic surfactant. EP-A-677575 further discloses the use, in a liquid peroxygen bleach composition, of an anionic surfactant to reduce skin itching of the user when it has come in contact with said composition. Acyl sarcosinates are mentioned amongst the anionic surfactants but no specific acyl sarcosinates are disclosed therein, nor exemplified.
Co-pending European patent application number 95203330.6 discloses a liquid bleaching composition comprising hydrogen peroxide, a liquid hydrophobic bleach activator, said composition being formulated as a microemulsion of said hydrophobic liquid bleach activator in a matrix comprising water, said hydrogen peroxide, a hydrophilic surfactant system comprising a nonionic surfactant and an anionic surfactant. Acyl sarcosinates are mentioned amongst the anionic surfactants but no specific acyl sarcosinates are disclosed therein, nor exemplified.
WO 95/27035 discloses a fabric washing detergent composition comprising an organic surfactant system (2%-40%), a non-aqueous system (0.5%-55%), a water-soluble polymeric detergency builder (0.1%14 5%) and water, wherein the surfactant system and the non-aqueous solvent together form a stable oil-in-water microemulsion. These compositions are useful as pretreatment products as well as main wash products. No acyl sarcosinates are disclosed, let alone long chain acyl sarcosinates. Also no peroxygen bleaches are disclosed.
WO 95/27033 and WO 95/27034 disclose particular microemulsions suitable to be used as pretreatment products. However, no acyl sarcosinates are disclosed, let alone long chain acyl sarcosinates. Also no peroxygen bleaches are disclosed.
EP 318 470 discloses a laundry pre-treatment composition in stick form (solid form) which is suitable for pre-spotting onto stained fabric before laundering. Bleach like percarbonates and perborates are disclosed. No acyl sarcosinates are disclosed, let alone long chain acyl sarcosinates.
U.S. Pat. No. 4,613,452 discloses emulsions containing an enol ester activator, hydrogen peroxide and nonionic and anionic emulsifiers. However, no acyl sarcosinates are disclosed, let alone long chain acyl sarcosinates.
EP 92 932 discloses emulsions comprising nonionic surfactants, a bleach, a bleach activator and, possibly anionic surfactants. However, no acyl sarcosinates are disclosed, let alone long chain acyl sarcosinates.